1. Field of the Invention
The invention relates to a method for increasing a rotational speed range of an ECM motor.
2. Description of the Related Art
ECM motor, commonly known as electronically commuted motor, for example, a brushless DC (BLDC) motor, has rated rotational speed. However, in use, the rotational speed of the motor is required to broaden (that is, to increase the maximum rotational speed) to adapt to more loads. A typical method for increasing the rotational speed of the motor includes: performing coordinate transformation on a phase current of the motor, conducting vector control to obtain currents Id and Iq on a rotor coordinate system, and regulating the value of Id to realize flux weakening control. However, such a method has tedious operation and occupies a tremendous computing resource of the microprocessor.
Thus, the method imposes high requirement on the microprocessor, thereby leading to high production cost; besides, the method necessitates accurate rotor position and accurate phase current information, thereby resulting in tedious operation.